(a) Technical Field of the Invention
The present invention relates to automatic pencil, and in particular, an automatic pencil allowing vertically depressing of a pencil lead to protruded from the tip of the automatic pencil.
(b) Description of the Prior Art
FIG. 1 is a conventional automatic pencil. The pencil has a hollow pencil shaft 1 having a bottom end linked to a pencil head 10. The center region of the pencil head 10 is being mounted with a pencil tip 11. The pencil head 10 is extended to mount a mounting cylinder 100 and is positioned with a pencil shaft. The pencil tip 11 is a banding ring 110 having frictional force to pull a pencil lead 12. A stopper is provided on the pencil tip 11 which is formed from two semi-circular stopping plates 13. The bottom end is extended until the slot within the top end of the pencil tip 11 and is mounted with a spring 14, allowing the pencil tip 11 to reciprocate upward and downward.
The bottom section of the stopping plates 13 is a slot 131 for the mounting of rolling ball 15, and is in combination with the inner wall of the inner cylinder 16. The top section of the inner cylinder 16 is mounted with a guiding tube 17 and the utmost end has a capping body 18. The top end of the capping body is an eraser 181.
Pencil leads 12 are inserted via the guiding tube 17. When the pencil leads 12 are depressed downwardly to the stopping plates 13, the depression of the pencil tip 11 when writing will automatically push out the pencil lead 12 without any other operation action, and can continuously in writing, which is very convenient in application. Conventional pencil leads are generally very long and when pencil leads are placed within the guiding tube 17, there is no any device to downward depress of the pencil leads, therefore the pencil shaft 1 has to be shaked so that the lead will side down to the stopping plate 13 and via the depressed pencil tip 11, the compression spring 14 causes the pencil tip 11 to inwardly contracted into the pencil shaft 1. When depression force is released, the spring 14 causes the tip 11 to protrude out from the pencil head 10 and at the same time, a pencil is withdraw at a great length. Repeating the action for several times, the pencil lead 12 is pushed out for utilization.
Whether or not there are pencil leads 12 contains in the pencil shaft 1, it can not be seen from outside of the pencil shaft 1, even the remaining of the lead cannot be determined. Thus, when the user opens the capping body 18 and inserts another pencil lead, the guiding hole 19 may be blocked and the pencil lead 12 is broken or is being blocked. In the conventional automatic pencil, no pencil lead cylinder is provided to the pencil shaft 1 and therefore, the pencil shaft 1 cannot hold extra pencil leads.